Isothermal annealing of color centers in irradiated polystyrene in vacuum and air atmospheres

Isothermal annealing of color centers in gamma ray irradiated (100 kGy) pol ystyrene in vacuum and air atmospheres is investigated. The color centers w ere measured by the optical absorptions at wavelength 400 nm. The absorptio n is assumed to be linearly proportional to the concentration of color cent er. The color center annihilation follows the second-order kinetic process for the vacuum annealing and the first-order kinetic process for the air an nealing. Both rate constants of annealing in vacuum and air satisfy the Arr henius plot. The activation energy is 54.29 kJ/mol for the former and 56.62 kJ/mol for the latter. (C) 2001 Elsevier Science B.V. All rights reserved.